Rev A.7 –2018/7 P2110-EVAL-01: Lifetime Power® Page 9
Energy Harvesting Development Kit for Wireless Sensors
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Wireless Sensor Board Voltage
The wireless sensor boards are regulated to operate at 3V. This voltage can’t be adjusted.
Transmitter Identification (TXID)
The TX91501 sends a unique identifier code along with the power that it outputs. This code can be used
for wireless sensor location tracking if devices are mobile. The wireless sensor board contains a circuit
for decoding this ID. If the wireless sensor board for some reason can’t read the ID, or there is no ID, it
sends an error code, and “---“ is displayed on the terminal.
Receiver Signal Strength Indicator (RSSI)
RSSI shows the actual power level that is being received at the antenna. This number is accurate from
0.04mW to 50mW. If the value is outside of the range, “---“ is displayed, denoting an RSSI read error.
Movement and reflections from various objects will affect the RSSI reading.
Temperature Sensor
A Murata NCP18XH103F03RB thermistor is used to measure temperature in the range of 25°F to 125°F.
A reading outside this range will constitute and error and “---“ is displayed. Also, if power is removed
from this sensor by removing the TEMP jumper on JP1, “---“ is displayed.
Humidity Sensor
A Honeywell HIH-5030 humidity sensor is used to measure humidity in the range of 15% to 85%, with 3%
accuracy. A reading outside this range will constitute and error and “---“ is displayed. Also, if power is
removed from this sensor by removing the HUMIDITY jumper on JP1, “---“ is displayed.
Light Sensor
A Vishay TEMT6000X01 ambient light sensor is used to measure luminance in the range of 10 lux to
99999 lux. A reading outside this range will constitute and error and “---“ is displayed. Also, if power is
removed from this sensor by removing the LIGHT jumper on JP1, “---“ is displayed.
External Sensor Port
The wireless sensor board has a terminal block (J3) for using external sensors. This port can supply
power to an external sensor, but the more power that the sensor uses, the longer the time period
between packets transmitted.
1. Connect the sensor wires to J3 as follows: (+) power, (S) sensor output, (-) ground.
2. Enable reading of the sensor port by connecting the EXTERNAL jumper pins on JP1.
WARNING: this port can only supply 3V to external sensors; do not apply more than 3V to EXTERNAL
port, as this will cause damage to the Wireless Sensor Board.
Current Measuring
JP2 is provided to allow for current usage measurements of the Wireless Sensor Board. The running
time of the board is too short (approx. 10ms) to allow for average current monitoring using a digital
multi-meter. An oscilloscope is required to witness the current usage. To measure current using a
current probe, remove JP2 and connect a test lead with hooks on either side from one pin to the other.
Attach the current probe to the test lead. If a current probe is not available, R18 is provided as a current
sensing resistor. R18 is a 10Ωresistor in parallel with JP2. With JP2 disconnected, the voltage across
R18 can be witnessed on the oscilloscope by connecting a voltage probe across JP2. The current can
then be calculated.